Sanitary napkins used to collect vaginal discharges and adult incontinent products are well known in the art. Various arrangements for individually packaging such absorbent articles are also known in the art.
Individually packaged sanitary napkins are disclosed in U.S. Pat. No. 3,973,567 issued to Srinivasan, et al. on Aug. 10, 1976; U.S. Pat. No. 4,917,675 issued to Taylor, et al. on Apr. 17, 1990, European Patent Application Publication No. 0357000 A1 published in the name of Umesh on Mar. 7, 1990, and in U.S. Pat. No. 4,556,146 issued Dec. 3, 1985, to Swanson et al. The Swanson, et al. patent discloses a trifolded wrapper which packages a sanitary napkin, covers adhesive on the outwardly oriented face of the backsheet, and may be used for disposing of the used sanitary napkin.
Other trifolded arrangements are known, such as that disclosed in U.S. Pat. No. 3,604,423 issued Sep. 14, 1971 to Fraser and in International Publication WO 89/02728 published Apr. 6, 1989 in the name of Froidh et al. Discarding used sanitary napkins enveloped in the packaging is also taught in the art. For example, International Publication WO 89/02729 published Apr. 6, 1989 in the name of Pigneul and U.S. Pat. No. 4,608,047 issued Aug. 26, 1986 to Mattingly disclose two packaging arrangements intended for this purpose.
The search for improved individual packages for disposable absorbent articles such as sanitary napkins has, however, continued. In particular, the search for a refastenable fastening system for such packages which satisfies all the desired criteria for such packages, has continued.
For instance, the design of adhesive fastening systems for individual disposable absorbent article packages concentrates on two major criteria which are generally opposed to each other: adhesive bond security and refastenability. It is the goal of such adhesive fastening systems to achieve both strong adhesive bond security (a bond which remains adhered to the package until it is desired to open the package to remove the absorbent article), and non-destructive removal of the tape upon opening the package for refastenability of the fastener when disposing of the absorbent article within the package after use.
It has generally been believed that the peel force of a pressure-sensitive adhesive tape from a substrate is one of the most important factors in determining how an adhesive fastening system actually performs during use. The peel force property shows that higher peel forces improve the bond security of the fastening system while also making it more difficult to remove without tearing the article to which the adhesive is fastened (that is, the landing surface or landing member). Thus, early solutions to providing an improved adhesive fastening system focused on balancing the peel force in order to optimize bond security and refastenability. One focus area was on adjusting the properties of the elements of the adhesive fastening system. Particularly, the tensile strength (tear resistance) of the landing surface, typically the unreinforced packaging material, was increased so that the packaging material could withstand high tensile stresses caused by the tape removal. However, such package materials tended to be rigid, noisy, expensive and more burdensome on material resources and the environment (require more materials). In other attempts, the tape properties were adjusted to increase contact area and lower peel force so as to not exceed the strength of the package material. These systems were expensive, inconvenient and had low bond security at low application pressure.
As the demand was made for high bond security adhesive fastening systems to meet the conditions placed upon the package of individual packaged absorbent articles, additional strength had to be added to the package material to avoid tearing the same. This additional strength was added to the package material by increasing its thickness, and/or by reinforcing it such as by laminating additional materials to the inside or outside of the package material in the fastening area.
Accordingly, it is an object of this invention to provide a refastenable fastening system for the package of an individually packaged absorbent article, such as a sanitary napkin. It is further an object of this invention to provide an individually packaged sanitary napkin which is easy for the user to open. It is also an object of this invention to provide an individually packaged sanitary napkin having packaging which may be used for disposal of a used product. Finally, it is an object of this invention to provide improved closure mechanisms for maintaining the package in a closed configuration for disposal.